Locomotive-fire-box arch.



. NICHOLSON.

E BOX ARCH.

APPLICATION FlLEnr.1Ar .i5

Pzlfeufd Jun@ 12, 191 f.

' 2 SHEETS-SHEET 1.

L L. MCHGLSON.

LOCOMOTIVE FIRE BOX ARCH.

APPLICATION FILED MAH15| 1916- narran srarns bannir y maca JOHN L. NICHOLSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO AMERICAN ARCI contraria,

OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

' LOCO1VIOTIVEFIRE-BOX ARCH.

Specification of Letters Patent.

Application alec March 15, 1916. serial No. 84,466.

To all whom t may concern:

Be it known that I, JOHN L. NICHOLSON, a citizen of the United States, and a resident of Chicago, Cook county, Illinois, have invented certain new and useful Improvements in and for LocomotiveFire-Box Arches, of which the following is a specification.

My invention relates to locomotive-boiler furnacesand has special reference to improvements in the refractory arches of such furnaces.

It is well known that the inclined front arch as ordinarily installed in a loco-motive boiler firebox performs the function of preventing the direct sweep of the flames from the fuellbed tothe flues, thus increasing the length of the flameway and the heating effect of the walls of the firebox. It is also -well known that such arches are effective in -the matter of causing a more uniform action of the draft through the fuel bed. Indeed, whereas under the old practice it was necessary to bank fuel upon the forward end of the grate, it is now customary to bank the fuel upon the rear end of the grate to oppose the more direct lifting effect of the inrushing air beneath the rear end of the arch. lilith-the exception of cinder holes, which are often placed at the lower ends of such arches they are made as nearly as possible imperforate. I speak here ofthe general practice, and not of the few'fis'olated eX- amples appearing in prior art patents which show arches containingv holes for the passage of hotvair, or for the deflection of cinders, or for the direct passage of gases fromgrate to flues. It is also now a well recognized fact that the practical efficiency of a refractory arch is in direct proportion to the mass of refractory material therein. t

The primary object'of my invention is to so improve the construction of such refractory arches that it shall be practicable to increase the massor volume of refractory material therein, and also the length of the arch. And further to provide an arch construction which shall present a large number of upwardly and laterally leading gas mixing ducts, which, being more or less uniformly distributed in the body 0f the arch, shall permit the firebox gases and products from each part of the grate to reach the combustion space above, the arch by more die l rect routes than around the rear end of the arch; and, whereby the products, after leave surface of the fuel bed shall be again supjected to a high temperature in the arch zone cross currents in opposition to the longi tudinally moving currents of gases from the Patented June f2, illllfft.

' ing the region of high temperature at the 6o l products pass through the arch `is' rear end of the rebox and insuring the uny;

form mixing of the combustible gases and' airin the combustion space above and foi ward of the arch. Afurther object Ofihy' i invention is' to construct an arch in such manner that it shall be self-cleaning, i, 1e.,

formed in the mannerindicated above, and

therefore characterized by the cross playing of conflicting streams of gases directly upon the top of the arch with the effect of preventing the lodgment and accumulation-of cindcrs and slag thereon. My further pigrpose in the construction indicated is to provide for the heating of the t'op of the arch in quite as effective a manner as the bottem of the arch, to the end that theY mass of refractory material shall to a greaterv extent' perform the function of interchanging heat with the gases and` products in thecombustion space, prior to theirentrance tojfthe flues.' notably the improvement of the compohent bricks for arches of various kindawill ap- Lpear hereinafter.

The nature and .broad characteristics of my invention as well as the vnovel forins and constructions, by means of which I attain the Objects and results above stated, will be readily understood on reference to the draw ings that form part of this specification, in

Other. objects ofl any inventionf.

which I have illustrated my invention in` the best form which I have thus fari-f le'vised In the drawings, Figure 1 is a longitudinal verticall section on the line Y--Y of Fig. 3, showing the rear end of a lfcomotive boiler and its Firebox, containing a front` arch embodying my invention ;-Fig. 2"is furenlarged detail Section thereof substantialty on.

the line X-X of Fig. 1;-Fig. 3 is a cross section on the line Z-Z of Fig. 1, showing my improved arch in course of construction ;-Fig. 4 is an inverted plan vievv4 of one of the main or body bricks of the arch Fig. 5 is a perspective underside vien1 of said body brick ;-Fig. 6 is an inverted plan View of one of the marginal bricks of the arch Fig. 7 is a cross section similar to Fig. 2, but showing a modified form of my invention Fig. 8 is an yunderside perspective view of one of the body bricks shown in Fig. 7 g-Fig.

9 is a further. section like unto Fig. 2, and

showing still another modification of the invention;-Fig. 10 is an underside perspective view of a body brick shown in Fig. 9;-Fig. 11 illustrates a modified form of said body brick ,-Fig 12 isa further modification thereof ;-a'nd, Fig. 13 is an under side perspective view of a body brick of the form shown in Fig. i). but lacking the lower sockets.

The parts of the typical locomotive boiler firebox or furnace shown in the drawings may be identified -as follows:-2, 8, and 4t are respectively the wrapper sheet, the throat sheet and the rear sheet of the boiler shell;-5 are the tlues;-6 is the flue sheet ;-and G the inner throat sheet;-7, 8, and 9, are respectively the rear sheet, the crown sheet and the side sheets of the firebox ;-1O is the mud ring which joins the vertical walls of the boiler shell and firebox;-11, is the grate, and 12 is the fuel door of the lirebox.

The familiar water-circulating arch tubes, 13, extend from the inner throat sheet, 6', to the upper part of the rear sheet, 7. They are spaced apart at distances fixed as hereinafter explained. The outer tubes of the group are usually somewhat nearer the side sheets, 9, than to the intermediate tubes of the group. Groups offour tubes are shown in the typical cross sectional views; For convenience, I shall refer to the intermediate arch tubes by the number 13, and to the outer arch tubes by the number 13a. These tubes, in conjunction with the side sheets, seri/e to support the component bricks and therewith complete the inclined arch.

As arches in this position are common, it is sufficient to point out that if the ordinary practice were followed the upper end of the inclined arch would not extend beyond the point indicated by the arrow, A, for it is ordinarily necessary to leave a large opening or gas passage between the upper end of thearch and the crown sheet, 8. Using my invention, it becomespraetieable to extend the arch farther toward the crown sheet, 8, and rear sheet, 7, and to leave only a comparatively small passage, B, betweemthe rear end of the arch and said sheets. By so doing I obviously greatly increase the mass of refractory material which is present in the lirebox for purposes of heat-sten age and interchange and to deflect the gases from the fuel bed toward the rear end of the firebox, to insure a proper distribution of heat upon all of the walls thereof. I should not be able to so greatly increase the extent and the mass of the refractory material were it not for the fact that I provide auxiliary gas passages in the body of the arch, and thereby compensate for the restriction of the passage, B, at the rear end of the arch. The auxiliary passages referred to are of peculiar form, to the end that their use shall not entail complications in either the making of the brick or the building of the arch, and to the further end thatthe gases instead of being permitted to move all in a general longitudinal direction in the iirebox, shall be largely dispersed in lateral directions as they pass from the tire-chamber, F, into the combustion chamber or space, C.

YAs explained hereinafter, I prefer that the component bricks shall themselves contain and form the auxiliary passages; and that this advantage shall be secured without entailing the use of body bricks of more than one pattern or design. While this is my preference, I have nevertheless illustrated several modified forms of the arch, composed of several kinds of bricks.

It. is very desirable that the component bricks shall be adapted to adjust or accommodate themselves-to irregularities in the supporting tubes, and always retain firm seats thereon. To this end I have invented special arch bricks which contain the auxiliary passages described, and yet present three point bearings upon the tubes, so that they are not detrimentally affected by irregula rities in their supports.

Referring now to Figs. 1, 2 and 3. It will be seen that the arch is composed of several longitudinal rows of bricks separated from one another by the arch tubes which support them. vWhere there are four arch tubes there are three longitlidinal rows of main or body bricks', 14,- and two rows of marginal bricks, 15. flhe body brickseof each row abut side to side. Their ends bear upon the arch tubes. The marginal bricks are similarly arranged side to side and they extend from' respective arch tubes to respective sido sheets, l'u'eferably in the inclined positions shown.

I prefer that all of the body bricks, 14, shall be of one pattern, and hence interchangeable. As hereinafter stated, I shape them so that they may occupy either of two positions, one an elevated positionl and the other a depressed position, upon their arch tubes. Likewise, I prefer that all of the marginal bricks, 15, shall be of the same size or pattern. A detailed description of one body brick 14, will serve for all of the body lio bricks; and,sin1ilarly av detailed description of one marginal brick will suflice for all of them.

Chiefiy for convenience in manufacture,

not necessarily, I provide the brick, 14, with only through the bottom and end vof the brick, vwhereas I prefer that the opposite shall be divided into. two parts, 14d, 14d, opening through the sides of the brick as welLas through the bottom ends thereof. A portion of full thickness remains between the recesses.

The passages are of less than one-half the length of the brick and are of lessy width than the brick. Thus -the bottom. 14h, is of a Y formation or shape. I shall refer to the portion, 14, as the stem of the Y shaped bottom and to the portions, 14", 14, as the arms thereof. One reason for shaping the brick in this manner is to insure the even shrinkage of the brick andto prevent the checking or cracking thereof during the firing process in the kiln. A second reason for so shaping the bottom of the brick is to provide it with three points of bearing upon lthe arch tubes which support it. The ends or terminals of the parts, 14e, and, 142 form such bearings and allow the brick to accommodate itselfto, and rest firmly upon, arch tubes which may or may not be in strict parallelism.

Two bearings or sockets, 14g, and, 14, are provided in each of said terminal positions. The distance between the sockets 14g, 14g, is such as to allow the relatively overhanging ends, 141, of the brick to rest upon 'the tops of the arch` tubes; while the distance "between the sockets, 14h, 14, is so ,much shorter that when they are used thebrick is elevated upon the tubes. In the lower or depressed position, the ends of the passages, 14, and, 14d, are closed by the tubes. The

elevation of the brick upon the sockets, 14h,

opens or exposes the ends of the recesses, 14e, and, 14, above the top of the tubes.

,The latter condition is depicted by the middle brick, 141, in Fig. 2. The outer bricks, 14, (which rest upon the tubes. 13, 13a), depict the depressed condition, `in which the passages are closed.

The use of bricks, 14, all of one pattern or size, in the `manner shown, is permitted by the depicted spacing of the arch tubes. It -Will be noted that the middle tubes,.13, are closer together than the tubes, 18, 13a. Thus the tubes 13, 13,`are adapted to support the middle brick in elevated position with its ends overlapping the bricks' ('14), which rest upon the tubes, 13, 13a. With the bricks in these positions the passages of the middle brick are open, and permit the upward and lateral movement of gases through the body of the arch.

The component bricks are of sizes which permit them to be passed through the fuel door, 12, and from this fact it will be undei-stood that the passages, 111, and 14d, are relatively minute and are not only constricted but are also tortuous and cause the subdivision, deflection and flow of the products toward the side sheets above the arch.

The eXtreme ends, 141, of the bricks, 14, are preferably beveled inwardly to limit the end contact between the bricks as they rest upon the tubes.

It will be understood that the bricks are assembled upon the arch tubes in the manner shown in Fig. 3, so that -the partial passages, 14, on one brick are completed by the like passages, 14d, of the adjacent bricks. However, no serious difficulty will .be encountered when the bricks are indiscriminately assembled; for the side, 14k, of any brick may quite as well serve as the side wall or closure of the partial passage or half cavity, 14, of any other brick.

While my invention is not limited to the I use of marginal bricks, 15, which are similar to the body bricks, I nevertheless much prefer to relieve the pressure at the sides of the lire-box by providing similar tortuous openings or passages through the marginal bricks. Thus each marginal brick, 15, is characterized by a Y-shaped bottom, 15a, a main recess or` passage, 15b, and end recesses, 15C, 156. 'I prefer that the brick shall taper toward and rest upon the side sheet, 9. The end, 15d, of the brick, should be rounded or point-ed to limit 'the end bearing of the brick to the stem, 15e, z'. e., to substantially a single point of bearing lon the side sheet, as shown in Fig; 6. The arms, 15f, of the Y-shaped bottom provide 'the other two points of bearing, as upon the tube, 13a. As shown, the recess, 155, opens above the tube, 13, and above the top of the body brick, 14, which rests thereon, in manner to cause the gases from the firechamber, F, to sweep laterally across the top of 'the arch.

The positions of the bricks, 14 and. 15, and their relations to the'side sheets and arch tubes of the firebox, and also the manner vof constructing the arch, are soI well l shown in Fig. 3 that further description thereof seems unnecessary.

The irregular line, F, in Fig. 1, represents the surface of the bed of fuel on the grate, 11. During the operation of the l0- coniotive there is a partial and fluctuating vacuum in the firebox.` As the products rise from the fuel bed the arch, as a whole, tends to deflect them toward the rear end of the arch. But. while the main sweep of the products is rearward and upwardlSU around the rear end of the arch, there is at the same time a continuous flow of products through the described tortuous passages in the body ofthe arch. The streams which emerge from the passages in the arch sweep the top of the arch and prevent the lodgment of cinders 'thereon and also forcibly admiX with the main stream moving forward from the passage, B. In this mandescribed, for the. middle row,

ner three principal operations are perforaned: First,-the partial vacuum, or low pressure, is equalized throughout the fireehamber, F;-second, the combustibles and air are forciblv admixed in and upon the underside of the arch and in the passages thereof;-and, third, the many streams of combustibles and air are violently admixed in the combustion chamber, C.

rl`he movement of the flames from the firebox through the body of the. arch, insures the uniform heating of the refractory material and a measurable improvement in the constancy of temperature in the combustion chamber, (l. The marked increase in the mass of refractory material made possible bylthe relief of pressure through the body of the arch results in maintaining a more constant temperature throughout the iirebox and in relieving the flues from the detrimental elfect of the cold air which ispadmitted when the fire door, 12, is opened. The equalization of' pressure in the 'firechamber, F, allows the carrying of a fuel bed which is comparatively thin and 0f uniform depth, with a consequent increase of efficiency.

My invention may be carried out with refractoryI bricks of different shapes, The middle brick, 17, and the marginal bricks, 18, shown in Fig. 7 are of the now well known Security types. The bricks, 19,' -19, are of a special type which I have invented for use with such bricks. The bricks,

19, are characterized by arch tube bearings,

19, and by preferably symmetrical, tortuous gas passages, 19, which open above said sockets and the supporting' tubes. The bricks of this form of perforated, gas miX- ing arch are assembled in much the same manner as shown in Fig. 8 and the streams of gases which emerge .from the passages, 19, obviously sweep transversely across the top of the arch.

' In the further modification shown in Fig. 9 I employ and substitute modified bricks, 20, in theouter rows. Inasmueh as the passages, 1,9", of the bricks,

19, must remain open, bricks, 20, are provided with low ends, 20', adjacent thereto and with high ends, 20, distant therefrom, the latter containing the essential passages, 20a. The low end of the brick, 20, may be .formed upon an incline, 20, to wedge against the middle arch tube, 13, or may be bricks, 19, of the form next above provided with a socket, 20c, as shown in Fi'g. 11. The outer end of the brick may contain either one socket, 20d, as shown in Fig. 11, or two sockets, 20e and 20f, as shown in 12. Obviously, the entire body of the arch may be made of the bricks, 20. I prefer that the brick, 20, shall be both strengthened and reduced in weight by the addition 'of inner-.end recesses, 20g, best shown in Fig. 10, but if desired these may be merged with the recess, 20a.

The brick, 14X shown in Fig. 13, needs no description beyond the fact that it is substantially identical with the bricks, 14;, ,of Fig. 2 except that it is of less thickness; as though the bottom part of theY brick, i4,

(Fig. 2) were removed to the level of the' horizontal dotted line at the left hand 'of Fig. 2. Such bricks can very well be substi- -tuted for the body bricks shown in Fig. 2.;

In further elucidation of the subject,.the following matters may be mentioned This form of arch will'increase theA mass of' refractory arch material, thereby increasing the regenerative action of the arch and maintaining a higher .and more uniform temperature in the'firebox.`

The `form of brick used allows the coinbustible gases to pass through the openings of the brick in small streams and to commingle above the arch, thereby insuring' a more intimate mixture of the different coml bustible gases with the oxygen present; and a more perfect combustion,`with anattendant saving in fuel and an increase in boiler efficiency. f

The openings provided in these special bricks more uniformly distribute and equalize thedraft over the entire surface of"I the fuel bed. This equal distribution allows the maintenance of a fuel bed of uniform thickness instead of the usual practice: of banking the fire to suit the draft distribution, thereby increasing the flow of .air through the grates and fuel bed with an {attendant 'increase in temperature. *J

This uniform distribution of draft lover a lire' bed of uniform depth will resultv in reducing the pressure drop'between the ash pan and fireoox, and cause a reductipn of cylinder back pressure (required to produce the draft) with a consequent increase in the power delivered by the cylinders and\ increase in engine etliciency.

The light" fuel bed of uniform thickrf` ss which is jnade possible by this uniform distribution of draft will tend to eliminate holes in the fuel bed, andthus prevent., the inrush of cold air which often v,results in' ticle/s of coal on the fuelwbed', thereby decreasing the losses due to incompletecom- Ibustlon of carbon and cindersand a 'reduc cumulation of cinders or slag the arch, thereby preventing the plugging l@ bom '-provided by these special tion in amount vof cinders discharged from "the stack and accununulated in. the smoke of the lower fiues, as often occurs with the present form of arch for the cinders and slag carried are swept up by these counter'- currents, carried through the flues and discharged. at the stack.

The special bricks herein describedwill y v be found tb be comparatively inexpensive and extremely .strong and durable.' Still other advantages will be apparentIJ- to those who are `skilled in the art.

Having thus described my invention, I claim as new and desire to secure by Letters Patent l. A locomotive boiler irebox, in combination with a refractory arch extending upwardly and rearwardly from the lower part oit the ue sheet of the tireboX toa point which restricts the opening between the arch and the crown sheet to an area not exceed ing and preferably less than the aggregate area of the lines and said arch containing preferably uniformly distributed upwardly and transversely extending passages whereby the lackvof area in the passage at the rear end of the arch is compensated and the products from the re chamber are subdivided ,into conicting longitudinal and transverse streams in the space above the arch and rearward of the iiue sheet.

2. A locomotive boiler irebox in combination with a refractory archextending upwardly and rearwardly from the lower part of the flue sheet of the lirebox and containing preferably ,uniformly distributed upwardly whereby the products fro'm the l'ire chamber are subdivided into coniiicting longitudinal and transverse streams in' the space above the arch and rearward 'of the flue sheet.

3.' A locomotive boiler rebox and its arch tubes,in combination with a refractory arch extending upwardly and rearwardly from the lower part of the flue sheet of the rebox vanclcomposed of .rows ofbricks resting upon said tubes and containing preferably uni- 55 form'ly distributed upwardly and trans v ersely extending lpassages whereby the products from the fire chamber are subdivided into conicting longitudinal and transverse streams in the space above the arch and rearward of the-.flue sheet.

' 4. -A locomotive boiler flrebox and its arch tubes, in combination with a refractory arch in` said rebox and'composed of high and low rows of `bricks resting upon said tubes *and the bricks havingopenings in and transversely extending passages their ends, whereby some of the products from the tire chamber are alloweduto pass through the arch and conflicting longitudi-v nal'and transverse streams are set up inthe space above the arch and rearward yof the flue sheet.

5. A locomotive boiler iirebox and longitudinal arch tubes therein, in combination with arefractory arch composed of longitudinal rows of bricks resting on said tubes,

alternate rows of said bricks being elevated above the others and containing upwardly and transversely extending passages whereby the lack of area in the passage at the rear end ofthe arch is compensated and the prodncts from thei lire chamber are subdivided intol conflicting longitudinal and transverse streams in* the space above the arch. 16. The improved arch component brick herein described having two arch tube sockets in its end, one above the other, and/ both opening downward. i

7. The improved arch component brick herein described having two arch/tube sockets, one above the other, irrle'ach end, all opening downward.' 8. The improved arch component brick herein described having two arch tube sockets in its end, one above' the er, anfd opening downward, andsaid/brick also/having a cavity opening through its end and bbttoml 9. The improvedarc/h-componentbrick herein described having open cavities yin its bottom, one of said cavities in one end and two of said cavities in the other end, all said cavities opening through the respective ends of the brick.

10. The improved arch .component brick herein described having a if-shaped bottom.

11. The improved arch component brick herein described having a Yshaped bottom andpresenting three bearings for engagement with spaced supports.

12. The improved arch -component brick herein described having` a Y-shaped bottom ,and containing gas passages at the side of the stem of its Y-shaped portion, and a single gas passage between the arms pf said portion. Y

13. The improved arch component brick herein Vdescribed having a iff-shaped ibottom and containing gas passages at the side of the stem of its Y-shaped portion, and a single gas passage between the arms pf said portion, said passages opening'through respeotive endsof the brick.

14. The improved arch component brick herein described having a fiat top and a Y- shaped bottom, the latter containing gas passages which open through'respective ends of the brick and the brick being provided with ,arch tube bearings at the ends ofthe arms and stem of its Y-*shaped bottom.

15. The improved arch component brick herein described( having a at top and a Y- 130 .y

shaped bottom, the latter containing gas passages which open through respective ends of the brick and the brick being provided With two arch tube bearings at the end of each arm and stem of its Ysl1aped bottom.

16. A locomotive boiler ireboX, in combination with a refractory arch extending upwardly and rearwardly from the lower part of the flue sheet of the firebox to a point which restricts the opening between the arch and the crown sheet to an area less than the aggregate area of the lues and said arch containing preferably uniformly distributed passages whereby the lack of area in the passage at the rear endof the arch is compensated and the products from the fire chamber are subdivided into conflicting longitudinal and transverse streams in the space above the arch and rearward of the flue sheet.

In testimony whereof, I have hereunto set my hand this 19th day of January, 1916.

JOHN L'. NICHOLSON. 

